Google Payment API - Enable an easy-to-use checkout experience for customers

My Charity Change - Round-up daily transactions & donate to charities

Giftbit Payment API - Stripe for gift cards

4thWall - A free Google Chrome extension that raises money for charities while you stream shows and movies right on your favorite websites.

Stripe - Online payment processing for internet businesses. Stripe is a suite of payment APIs that powers commerce for online businesses of all sizes. Use Stripe’s payment platform to accept and process payments online for easy-to-use commerce solutions.

Hedado - Donate like a boss with Hedado!